// clang-format off
/* ----------------------------------------------------------------------
   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
   https://www.lammps.org/, Sandia National Laboratories
   Steve Plimpton, sjplimp@sandia.gov

   Copyright (2003) Sandia Corporation.  Under the terms of Contract
   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
   certain rights in this software.  This software is distributed under
   the GNU General Public License.

   See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */

#include "compute_global_atom.h"

#include "arg_info.h"
#include "atom.h"
#include "error.h"
#include "fix.h"
#include "input.h"
#include "memory.h"
#include "modify.h"
#include "update.h"
#include "variable.h"

using namespace LAMMPS_NS;

enum{VECTOR,ARRAY};


#define BIG 1.0e20

/* ---------------------------------------------------------------------- */

ComputeGlobalAtom::ComputeGlobalAtom(LAMMPS *lmp, int narg, char **arg) :
  Compute(lmp, narg, arg),
  idref(nullptr), which(nullptr), argindex(nullptr), value2index(nullptr), ids(nullptr),
  indices(nullptr), varatom(nullptr), vecglobal(nullptr)
{
  if (narg < 5) error->all(FLERR,"Illegal compute global/atom command");

  peratom_flag = 1;

  // process index arg

  int iarg = 3;
  ArgInfo argi(arg[iarg]);

  whichref = argi.get_type();
  indexref = argi.get_index1();
  idref = argi.copy_name();

  if ((whichref == ArgInfo::UNKNOWN) || (whichref == ArgInfo::NONE)
      || (argi.get_dim() > 1))
    error->all(FLERR,"Illegal compute global/atom command");

  iarg++;

  // expand args if any have wildcard character "*"

  int expand = 0;
  char **earg;
  int nargnew = utils::expand_args(FLERR,narg-iarg,&arg[iarg],1,earg,lmp);

  if (earg != &arg[iarg]) expand = 1;
  arg = earg;

  // parse values until one isn't recognized

  which = new int[nargnew];
  argindex = new int[nargnew];
  ids = new char*[nargnew];
  value2index = new int[nargnew];
  nvalues = 0;

  for (iarg = 0; iarg < nargnew; iarg++) {
    ArgInfo argi2(arg[iarg]);

    which[nvalues] = argi2.get_type();
    argindex[nvalues] = argi2.get_index1();
    ids[nvalues] = argi2.copy_name();

    if ((which[nvalues] == ArgInfo::UNKNOWN) || (which[nvalues] == ArgInfo::NONE)
        || (argi2.get_dim() > 1))
      error->all(FLERR,"Illegal compute slice command");

    nvalues++;
  }

  // if wildcard expansion occurred, free earg memory from expand_args()

  if (expand) {
    for (int i = 0; i < nargnew; i++) delete [] earg[i];
    memory->sfree(earg);
  }

  // setup and error check both index arg and values

  if (whichref == ArgInfo::COMPUTE) {
    int icompute = modify->find_compute(idref);
    if (icompute < 0)
      error->all(FLERR,"Compute ID for compute global/atom does not exist");

    if (!modify->compute[icompute]->peratom_flag)
      error->all(FLERR,"Compute global/atom compute does not "
                 "calculate a per-atom vector or array");
    if (indexref == 0 &&
        modify->compute[icompute]->size_peratom_cols != 0)
      error->all(FLERR,"Compute global/atom compute does not "
                 "calculate a per-atom vector");
    if (indexref && modify->compute[icompute]->size_peratom_cols == 0)
      error->all(FLERR,"Compute global/atom compute does not "
                 "calculate a per-atom array");
    if (indexref && indexref > modify->compute[icompute]->size_peratom_cols)
      error->all(FLERR,
                 "Compute global/atom compute array is accessed out-of-range");

  } else if (whichref == ArgInfo::FIX) {
    auto ifix = modify->get_fix_by_id(idref);
    if (!ifix)
      error->all(FLERR,"Fix ID {} for compute global/atom does not exist", idref);
    if (!ifix->peratom_flag)
      error->all(FLERR,"Compute global/atom fix {} does not calculate a per-atom vector or array", idref);
    if (indexref == 0 && (ifix->size_peratom_cols != 0))
      error->all(FLERR,"Compute global/atom fix {} does not calculate a per-atom vector", idref);
    if (indexref && (ifix->size_peratom_cols == 0))
      error->all(FLERR,"Compute global/atom fix {} does not calculate a per-atom array", idref);
    if (indexref && indexref > ifix->size_peratom_cols)
      error->all(FLERR, "Compute global/atom fix {} array is accessed out-of-range", idref);

  } else if (whichref == ArgInfo::VARIABLE) {
    int ivariable = input->variable->find(idref);
    if (ivariable < 0)
      error->all(FLERR,"Variable name for compute global/atom does not exist");
    if (input->variable->atomstyle(ivariable) == 0)
      error->all(FLERR,"Compute global/atom variable is not "
                 "atom-style variable");
  }

  for (int i = 0; i < nvalues; i++) {
    if (which[i] == ArgInfo::COMPUTE) {
      int icompute = modify->find_compute(ids[i]);
      if (icompute < 0)
        error->all(FLERR,"Compute ID for compute global/atom does not exist");
      if (argindex[i] == 0) {
        if (!modify->compute[icompute]->vector_flag)
          error->all(FLERR,"Compute global/atom compute does not "
                     "calculate a global vector");
      } else {
        if (!modify->compute[icompute]->array_flag)
          error->all(FLERR,"Compute global/atom compute does not "
                     "calculate a global array");
        if (argindex[i] > modify->compute[icompute]->size_array_cols)
          error->all(FLERR,"Compute global/atom compute array is "
                     "accessed out-of-range");
      }

    } else if (which[i] == ArgInfo::FIX) {
      auto ifix = modify->get_fix_by_id(ids[i]);
      if (!ifix)
        error->all(FLERR,"Fix ID for compute global/atom does not exist");
      if (argindex[i] == 0) {
        if (!ifix->vector_flag)
          error->all(FLERR,"Compute global/atom fix {} does not calculate a global vector", ids[i]);
      } else {
        if (!ifix->array_flag)
          error->all(FLERR,"Compute global/atom fix {} does not calculate a global array", ids[i]);
        if (argindex[i] > ifix->size_array_cols)
          error->all(FLERR,"Compute global/atom fix {} array is accessed out-of-range", ids[i]);
      }

    } else if (which[i] == ArgInfo::VARIABLE) {
      int ivariable = input->variable->find(ids[i]);
      if (ivariable < 0)
        error->all(FLERR,"Variable name for compute global/atom does not exist");
      if (input->variable->vectorstyle(ivariable) == 0)
        error->all(FLERR,"Compute global/atom variable is not vector-style variable");
    }
  }

  // this compute produces either a peratom vector or array

  if (nvalues == 1) size_peratom_cols = 0;
  else size_peratom_cols = nvalues;

  nmax = maxvector = 0;
  vector_atom = nullptr;
  array_atom = nullptr;
}

/* ---------------------------------------------------------------------- */

ComputeGlobalAtom::~ComputeGlobalAtom()
{
  delete [] idref;

  delete [] which;
  delete [] argindex;
  for (int m = 0; m < nvalues; m++) delete [] ids[m];
  delete [] ids;
  delete [] value2index;

  memory->destroy(indices);
  memory->destroy(varatom);
  memory->destroy(vecglobal);
  memory->destroy(vector_atom);
  memory->destroy(array_atom);
}

/* ---------------------------------------------------------------------- */

void ComputeGlobalAtom::init()
{
  // set indices of all computes,fixes,variables

  if (whichref == ArgInfo::COMPUTE) {
    int icompute = modify->find_compute(idref);
    if (icompute < 0)
      error->all(FLERR,"Compute ID for compute global/atom does not exist");
    ref2index = icompute;
  } else if (whichref == ArgInfo::FIX) {
    int ifix = modify->find_fix(idref);
    if (ifix < 0)
      error->all(FLERR,"Fix ID for compute global/atom does not exist");
    ref2index = ifix;
  } else if (whichref == ArgInfo::VARIABLE) {
    int ivariable = input->variable->find(idref);
    if (ivariable < 0)
      error->all(FLERR,"Variable name for compute global/atom does not exist");
    ref2index = ivariable;
  }

  for (int m = 0; m < nvalues; m++) {
    if (which[m] == ArgInfo::COMPUTE) {
      int icompute = modify->find_compute(ids[m]);
      if (icompute < 0)
        error->all(FLERR,"Compute ID for compute global/atom does not exist");
      value2index[m] = icompute;

    } else if (which[m] == ArgInfo::FIX) {
      int ifix = modify->find_fix(ids[m]);
      if (ifix < 0)
        error->all(FLERR,"Fix ID for compute global/atom does not exist");
      value2index[m] = ifix;

    } else if (which[m] == ArgInfo::VARIABLE) {
      int ivariable = input->variable->find(ids[m]);
      if (ivariable < 0)
        error->all(FLERR,"Variable name for compute global/atom "
                   "does not exist");
      value2index[m] = ivariable;
    }
  }
}

/* ---------------------------------------------------------------------- */

void ComputeGlobalAtom::compute_peratom()
{
  int i,j;

  invoked_peratom = update->ntimestep;

  // grow indices and output vector or array if necessary

  if (atom->nmax > nmax) {
    nmax = atom->nmax;
    memory->destroy(indices);
    memory->create(indices,nmax,"global/atom:indices");
    if (whichref == ArgInfo::VARIABLE) {
      memory->destroy(varatom);
      memory->create(varatom,nmax,"global/atom:varatom");
    }
    if (nvalues == 1) {
      memory->destroy(vector_atom);
      memory->create(vector_atom,nmax,"global/atom:vector_atom");
    } else {
      memory->destroy(array_atom);
      memory->create(array_atom,nmax,nvalues,"global/atom:array_atom");
    }
  }

  // setup current peratom indices
  // integer indices are rounded down from double values
  // indices are decremented from 1 to N -> 0 to N-1

  int *mask = atom->mask;
  int nlocal = atom->nlocal;

  if (whichref == ArgInfo::COMPUTE) {
    Compute *compute = modify->compute[ref2index];

    if (!(compute->invoked_flag & Compute::INVOKED_PERATOM)) {
      compute->compute_peratom();
      compute->invoked_flag |= Compute::INVOKED_PERATOM;
    }

    if (indexref == 0) {
      double *compute_vector = compute->vector_atom;
      for (i = 0; i < nlocal; i++)
        if (mask[i] & groupbit)
          indices[i] = static_cast<int> (compute_vector[i]) - 1;
    } else {
      double **compute_array = compute->array_atom;
      int im1 = indexref - 1;
      for (i = 0; i < nlocal; i++)
        if (mask[i] & groupbit)
          indices[i] = static_cast<int> (compute_array[i][im1]) - 1;
    }

  } else if (whichref == ArgInfo::FIX) {
    if (update->ntimestep % modify->fix[ref2index]->peratom_freq)
      error->all(FLERR,"Fix used in compute global/atom not "
                 "computed at compatible time");
    Fix *fix = modify->fix[ref2index];

    if (indexref == 0) {
      double *fix_vector = fix->vector_atom;
      for (i = 0; i < nlocal; i++)
        if (mask[i] & groupbit)
          indices[i] = static_cast<int> (fix_vector[i]) - 1;
    } else {
      double **fix_array = fix->array_atom;
      int im1 = indexref - 1;
      for (i = 0; i < nlocal; i++)
        if (mask[i] & groupbit)
          indices[i] = static_cast<int> (fix_array[i][im1]) - 1;
    }

  } else if (whichref == ArgInfo::VARIABLE) {
    input->variable->compute_atom(ref2index,igroup,varatom,1,0);
    for (i = 0; i < nlocal; i++)
      if (mask[i] & groupbit)
        indices[i] = static_cast<int> (varatom[i]) - 1;
  }

  // loop over values to fill output vector or array

  for (int m = 0; m < nvalues; m++) {

    // output = vector

    if (argindex[m] == 0) {
      int vmax;
      double *source;

      if (which[m] == ArgInfo::COMPUTE) {
        Compute *compute = modify->compute[value2index[m]];

        if (!(compute->invoked_flag & Compute::INVOKED_VECTOR)) {
          compute->compute_vector();
          compute->invoked_flag |= Compute::INVOKED_VECTOR;
        }

        source = compute->vector;
        vmax = compute->size_vector;

      } else if (which[m] == ArgInfo::FIX) {
        if (update->ntimestep % modify->fix[value2index[m]]->peratom_freq)
          error->all(FLERR,"Fix used in compute global/atom not computed at compatible time");
        Fix *fix = modify->fix[value2index[m]];
        vmax = fix->size_vector;

        if (vmax > maxvector) {
          maxvector = vmax;
          memory->destroy(vecglobal);
          memory->create(vecglobal,maxvector,"global/atom:vecglobal");
        }

        for (i = 0; i < vmax; i++)
          vecglobal[i] = fix->compute_vector(i);

        source = vecglobal;

      } else if (which[m] == ArgInfo::VARIABLE) {
        vmax = input->variable->compute_vector(value2index[m],&source);
      }

      if (nvalues == 1) {
        for (i = 0; i < nlocal; i++) {
          vector_atom[i] = 0.0;
          if (mask[i] & groupbit) {
            j = indices[i];
            if (j >= 0 && j < vmax) vector_atom[i] = source[j];
          }
        }
      } else {
        for (i = 0; i < nlocal; i++) {
          array_atom[i][m] = 0.0;
          if (mask[i] & groupbit) {
            j = indices[i];
            if (j >= 0 && j < vmax) array_atom[i][m] = source[j];
          }
        }
      }

    // output = array

    } else {
      int vmax;
      double *source;
      int col = argindex[m] - 1;

      if (which[m] == ArgInfo::COMPUTE) {
        Compute *compute = modify->compute[value2index[m]];

        if (!(compute->invoked_flag & Compute::INVOKED_ARRAY)) {
          compute->compute_array();
          compute->invoked_flag |= Compute::INVOKED_ARRAY;
        }

        double **compute_array = compute->array;
        vmax = compute->size_array_rows;

        if (vmax > maxvector) {
          maxvector = vmax;
          memory->destroy(vecglobal);
          memory->create(vecglobal,maxvector,"global/atom:vecglobal");
        }

        for (i = 0; i < vmax; i++)
          vecglobal[i] = compute_array[i][col];

        source = vecglobal;

      } else if (which[m] == ArgInfo::FIX) {
        if (update->ntimestep % modify->fix[value2index[m]]->peratom_freq)
          error->all(FLERR,"Fix used in compute global/atom not "
                     "computed at compatible time");
        Fix *fix = modify->fix[value2index[m]];
        vmax = fix->size_array_rows;

        if (vmax > maxvector) {
          maxvector = vmax;
          memory->destroy(vecglobal);
          memory->create(vecglobal,maxvector,"global/atom:vecglobal");
        }

        for (i = 0; i < vmax; i++)
          vecglobal[i] = fix->compute_array(i,col);

        source = vecglobal;

      } else if (which[m] == ArgInfo::VARIABLE) {
        vmax = input->variable->compute_vector(value2index[m],&source);
      }

      if (nvalues == 1) {
        for (i = 0; i < nlocal; i++) {
          vector_atom[i] = 0.0;
          if (mask[i] & groupbit) {
            j = indices[i];
            if (j >= 0 && j < vmax) vector_atom[i] = source[j];
          }
        }
      } else {
        for (i = 0; i < nlocal; i++) {
          array_atom[i][m] = 0.0;
          if (mask[i] & groupbit) {
            j = indices[i];
            if (j >= 0 && j < vmax) array_atom[i][m] = source[j];
          }
        }
      }
    }
  }
}

/* ----------------------------------------------------------------------
   memory usage of local atom-based array
------------------------------------------------------------------------- */

double ComputeGlobalAtom::memory_usage()
{
  double bytes = (double)nmax*nvalues * sizeof(double);
  bytes += (double)nmax * sizeof(int);                    // indices
  if (varatom) bytes += (double)nmax * sizeof(double);    // varatom
  bytes += (double)maxvector * sizeof(double);            // vecglobal
  return bytes;
}